A coepoeation op



A. J. LIEBENBERG ELEVATOR LEVELING cou'mon April 26 1927. 1,626,290

Filed Dec. 13, 1924 3 Sheets-Sheet 1 uvcnfo;

April 26. 1927.

A. J. LIEBENBERG ELEVATOR LEVELING CONTROL Filed Dec. 13, 1924 3 Sheets-Sheet 2 April 26. 1027. 1,626,290

WWW

Patented Apr. 26, 1927.

UNITED STATES PATENT OFFICE.

ARTHUR .T. LIEBENBERG, OF CINCINNATI, OI IIO, ASSIGNOI TO THE WARNER ELE VATOB, MANUFACTURING COMPANY, OF CINCINNATI, OHIO, A. CORPORATION OF OHIO. l

ELEVATOR-LEVELING CONTROL.

Application filed December 13, 1924. Serial No. 755,791.

This invention relates generally to improvements in elevators and particularly to motor control systems therefor, the principal objectof the invention being to provide means for obtaining accurate leveling and stopping of the car at the given floor or landing, and for automatically obtaining slow or CIZQWFSPQGd of the elevator within a leveling zone of' a landing. A 1

Another object is to provide for-a general manual C'OIltIOlfOf the elevator hoisting motor through a switch stationed in the car and-for an automatic car landihg control, for a landing leveling and within a landing Zone effective afterI-the manually operated car switch-has been brought to a neutral position for stoppingat a determined levell Another object-of the invention is 'to provideo an electric motor for elevator car hoisting capable of propelling the elevator car at various rates of speed for general service and at a low rate for car landing leveling purposes, the moior control for general service governed by a'manually operated car switch in conjunction with an automatically operated controller for current reversing starting resistance and motor'acceleration and motor actuation controlwithin-a'land ing zone when'the car switch is thrown to neutral for a landing control.-

An important feature of the invention resides in the use of-rnotors'ot'the shuntwound interpole type, having two identical :1 r1 natu re windings and commutators, including electrtiauagnetic means for alternate l v obtaining parallel and series connections of the winding respectively forobtaining relatively fast speeds, -as well as shin-"speeds with low starting current,

Another feature of theinvcntion is the use of IHOtOlSOf the above mentioned type, or of separate motors having identical 1: rma ture windings and commutatois connected in a similar manner, in conjunction with electro-magnetic' means for changin the relations of the armature'windings relative to one another and to certain starting resistances, whereby the armature windings can be put in series or parallel relation for obtaining a reduction of speed of elevator travel in one iIlSil'JIlCC'll-Iltl an increase of speed in the other.

Another feature is the provision of electro-magnet-ic means carried by the car, operable by a cam or like device placed at each floor, and adapted for control by'the car switch, to obtain and automatically maintain reverse slow leveling movementsof the car while the same is in a leveling zone Another feature is the provision of'afloor seiector device in electrical connection with the electro-magnetic control means carried by the car, the said'selector acting toregu late or control the action of the electromagnetic means, and said selectondevic'e being in turn mechanically driven by the car and counter-weight.

Another feature of the invention is'the provision of means for automatically break; mg all circuits through the electro-inagnetically operable'leveling means and leveling switch, carried by the car, when the -car switch handle is moved to any other than the leveling position, in this instance to the neuiral position, thus providing for resump tion of ordinary elevator control' athrough the car switch at the will of the operator.

Other objects 'and certain I advantages will be presented in the descriptionof the drawngs forming a partof this specification, and n said drawings: I

F igure 1 is a diagrammatic view illustrat ing' an embodiment of the invention as -ap-' plied to a freight elevator.

Figure 2 is an elevationeoi the leveling switchinounted'upen and movable vwith the elevator" car. 4

l igurc 3 is a side vieivof'tlie same.

Figuri-i 4 is a verticalseetional view of one of the circuit-closing contact switches, one of which is mounted at each floor actu aterl by a 'cam carried by the elevator car.

Figure 5 is a vertical section approxi u'iately on line 5 relation of the contact elements.

Figure 6 is a'fraglnentary view showing the upper portion of the floor selector stand illustrating its eneral arrangement, operated by a cable rum, the cable therefor attached at one end to the elevator and the opposite end to a weight.

Figure 7 is an enlarged central vertical Section of Fig. (i. i

Figure 8 is a face view of the car switch with the cover removed, showing the.-ar-' 5, of Fig. 4, showing the rangement of the contacts and contact lingers.

Figure 9 is a vertical sectional view of Fig. 8.

The system combines for the control of elevator hoisting motor a manually operatedelevator car switch for obtaining the general control of the elevator, and an elevator car fioor leveling construction control operative after the car switch has been thrown to neutral or car stopping control position and the car is within a determined proximity to a landing to bring the car floor at an exact level with the landing. The system requires no presetting for a determined floor stopping and leveling operation and no slowing down and stopping for each floor landing, nor is the automatic floor leveling control effective .ior any floor while the-operator retains the car switch in an op erative. controlling position, except at hatchway limits, so that the operator can pass an-y floor landings at which no stopping-is desired and at any speeds at which the elevator can be run.

The; system in the present instance employs' a single motor of varying speed type in which the general controller mechanism operated hythe car switch controls circuits for establishing two motor speeds as high and low. for the hoisting services, and the automatic leveling mechanism controlling circuit for establishing a third motor speed as very low or as may be termed a crawl speed for car leveling service.

The .particular motor disclosed herein represents a. shunt wound interpole type, with an armature .having two identical windings and two: cormnutators. For the normalspeeds-the control connects the ar- -mature windings in parallel for the slow car running speed, and with the shunt field control the high speed is obtained. Throwin'g armature circuits in series and with full ,fieldthc very low. or crawl speed is obtained, th e double armature windings pmviding for a very slow speed with a lowstarting current. r

The controller for the motor aside from the controlling mechanism for establishing the circuits for running the motor at its very. low or crawling speed is of a commercial typehaving magnet operated contactors for direction control, magnet operated switch for motor slow speed accelerating or starting control and high speed motor. accelerating control and to prevent sudden motpr reverse when in highspeed and possesses such otheufeatures forsafety and efficiency characteristic of elevator motor controllers. g For making a landing the operator as he. approaches the landing throws the car switch to neutral, and as the automatic leveling. control is effective within a determined distance above and below the land mg it is only essential that the operator govern his time of car switch control to bring the car within the automatic leveling zone in positioning the car switch to neutral.

The car is provided witha-cam shoe which engages with an electric circuit controlling switch designated as a floor switch located at the landing, a floor switch being provided for each landing at which automatic leveling is desired. The cam shoe is of a length for operating the electric switch within a determined range above and below the landing. This swit'clroperates in conjunction with a dial switchoperated by a drum having a cable connection with the elevator car to select the direction in which the car will have to move to level up with ala-nd-ing and also serve as a. safety device. This dial switch provides a contact finger for each floor switch.

The car is provided with an electric circuit controllingswitch mechanically! and electrically operated, for mechanical operation .engaging a stationary cam shoe appropriately mounted in the elevator hatchway, one for each! landing, which operates in alternate circuit closing direction to break; the motor circuit or for motor starting'control in appropriate forward or reversedircctions, the switch being in electric circuit connection with the dial switch when in either of its closed positions, the cam shoe throwing the switchto its closed position for a continued or slow up travel of the elevator when the car switch-has been moved to its neutral position for making a landing, and permitting the switch to cut out to break the motor controlling circuit, forv automatic leveling. Should the car-move up beyond the cam shoe the switch-is free to move to a closed or cut ill position, for a down or reverse motor; control, until again thrownto cut; out position. by the cam shoe. The switch is also operated electrically by a magnetiorholding its movable switch element in which it will not abruptly engage the cam shoe in a through car runor passing any gi en 7 floor without.- stopping. The machanically operated car switch, dial switch and floor switch all conjunctively control the motorcontrolling. circuits through the carswitch when thecar switch is in neutral position. and although operative are inef fective when the car switch is in a controlling position.

The motor used herein is of a shunt wound inter-polartype in which the armature has two identical windings and commu-tators. lt is obvious that two identical motors could be used and such use is contemplated, the object, 0f, the double winding. being to secure slow or crawl speed with a low starting current in the leveling zone, and to further ilk) obtain ordinary elevator speeds when the elevator is traveling between the leveling zones or at any time when the electro-mechanical leveling mechanism or apparatus is inoperative.

For purposes of illustration, the motor shown is of the shunt wound interpolar type, the identical armatures and windings being respectively numbers 1 and 2, and the a'rmature terminals being indicated at 4 and 7, and 5 and 8. Arrangements are made for a control to alternately connect the motor (ll'lflii' ture windings in parallel or in series. When the armature windings are connected in parallel the motor control is primarily through the car switch and controller for the general car running service, and when in series for theautomatic leveling control after the car switch is in neutral. In the series connection a resistance 9 is inserted in series with the starting resistance of the controller which reduces the current amperage without affecting the torque. In actual practice the leveling mechanism is set by putting full load on the car and adjusting ,the resistance 9 until enough current goes through the armature to give the necessary torque to move the car. The motor therefore for leveling operates with a-. low starting current and crawl speed. For example, the'armature rotates at 150 R. P. M. with a full field when in series, and when in parallel a rotation of 300 R. P. M. is obtained and from this speed, speeds up to 900 R. P. M. are obtainable by shunt field control.

The torque of any motor is the product of the efi'ective number of armature ampere turns anda constant which is influenced by field density, air gap, and the like. .An ordinary 220 volt armature motor has an armature: wound with 100 elfective turns. A starting torque necessary to move the load requires a starting current of 100 amperes. This current-is secured by placing such a resistance 9 in series with the armatures as will fix the starting current at the '100 amperevalue. Thus, there are 100 armature turns times 100 amperes which equals 10.000

armature ampere turns, giving, say, a starting torque of 100 foot pounds.- \Vith the armature wound double it will have two windings of 100 turns each connected to separate comnuitators. \Vith the two wind ings connected in parallel there will be only 100 effective turns. On the other hand, if the two windings are connected in series and the same starting resistance 9 is used, there will not be 100 ampere turns but 200 turns. which changes the 10,000 armature ampere turns to 200 multiplied by 1.00, or 20,000 armature ampere turns. The starting torque has, therefore, been increased from 100 to 200 foot pounds, and starting resistance 9 is in series with starting resistance 23 which cuts the current down to ampcres leaving the torque the same. The starting resistance 23 is controlled in a well known manner by an electromagnet not shown for section-ally cutting out the re sistance as the motor accelerates.

In the drawing, E indicates the elevator car having connected therewith the hoisting cable C and counterweight WV, these parts being of ordinary construction and shown merely as illustrative of the application of the principles of my invention to the operation 01' an elevator. A floor selector F as part of an electro mechanical leveling apparatus is also provided (see Figs. 1. 6 and 7) for controlling the leveling operation and is mechanically driven by the car and counterweight by means of a cable assing around a drum keyed to a shaf t 61, said shaft also carrying-a worm 62 in driving connection with a worm wheel 63 keyed to a dial shaft 64. The dial shaft has keyed thereto at the opposite end a disk 65 to which are in turn ad1ustably and removably attached. in spaced relation, a series of pairs of fingers 66 of conducting material, each finger adapted to support renewable spring pressed brushes at its extremity, the brushes being pressed against circular, conducting contact strips 51, 52. Each of these strips is insulated and is adapted to be independently electrically connected in circuit with other parts of the device, through the fingers 66, as shown in Fig. 1, one strip acting. in conjunction with other elements to control elevator travel in up direction, and. the other strip to control down direction, according to the relative position of the fingers with respect thereto. The strips are mounted in a manner-to provide a gap 67 between adjacent extremities, adapted to be bridged by a pair of fingers as the elevator reaches floor level. Space plates 68 are provided to form the gap, which'plat-es may be replaced when worn-Iby arcingi Each plate is electrically connected. with its corresponding plate 51,'52. VVhen' the elevator is aligned with the'given floor, one finger of any given pair lies upon its respective strip immediately adjacent the extremity of the strips at the opposite side of the gap whereby circuit is maintained through the floor selector. This scheme provides circuit control means correlated to elevator movement and mechanically operable by the elevator for controlling the circuits and for obtaining accurate registration between the elevator and a given floor, the selector finger acting, by crossing from one side of the gap to the other, to make such circuits as will cause upward or downward car travel according as the fingers engage the plate 51 or 52, ant finally acting to stop the car at the proper level when the fingers bridge the gap, as shown in Figs. 1 and 6. In the diagram, for convenience, single fingers only have lorbeen shown. It is understood, however, that it is preferable to use the double finger arrangement.

The fioor selector controls the up and down movement of the car at or near the floor level or in the leveling zone through a switch 26 mounted upon the car and providing two pairs of contacts LU, LU", LD, L1), in pairs at opposite sides of a switch arm alternately cooperating with said contacts. One contact of each is in circuit connection with the car switch as shown in Fig. 1, and the second contact of each connects with respective contact bars of the fioonselector, for a control of the motor in a leveling zone.

In order that the circuit through the leveling switch 26 and floor selector F may be had only when the car is in the leveling zone, a; switch 24 is provided for each floor and each is-adapted-to be mechanically closed by the car when the car platform is adjacent. a given floor and as the car enters the leveling zone. To this end, normally open circuit closing switches 24 are provided having rollers engageable by a cam or trip 25' mounted upon the car for closing the circuit through its switches. The switches are identical in construction, and one is shown: detail in Figs. 4 and 5, and comprises a lever pivoted as at 71 intermediate its ends to a suitable casing, the lever havinga pair of separate yieldable contact members 72', 73, in circuit connectionmounted upon insulator blocks fixed upon the levers. These contacts are engageable respectively with stationary contacts or terminals 4.2, 43, suitably mounted within a switch easing.

- Each terminal 42 of each of the floor switches is in circuit connection with the respective finger or pair of companion fingers of the floor selector and each terminal 43 of each of the floor switches in circuit connection with the negative side of the main lineas at 40 (see Fig. 1). When the car cam 25 engages the roller the arm is oscillated to bring the contacts together to close the circuit through the floor switch.

The leveling switch is shown in Figs. 2 and. 3 and comprises a base attachable to the car, said base having horizontally jourualed thereon an operating'shaft S0 to one extremity of which is pinned an operating arm 81, providing a terminal roller engage able by any one of the fioor cams 28 for throwin the operating shaft incne direction anholding the same in thrown position during the leveling period, and also for causing alternate engagement of the circuit closing element of the switch with the switch contacts. Two pairs of yieldable contacts respectively LU, LU, and LD and LD, are mounted upon a stationary insulator block, the members of each pair adapted to be bridged and electrically connected by a metallic element 82 mounted upon an extension of a rod 83 held at the outer end of an arm 84 in turn pinned to the operating shaft and movable therewith. The rod 83 is furthermore extended at the opposite side of the arm and traverses an armature 85 pivoted upon the shaft 80. The armature is adapted to be drawn to the position shown in Fig. 2, to dispose the metallic element 82 in a position to avoid the rollers of the arm 81 engagino with the floor cam when the car is under the car switch manual control. The magnet is always energized when the car switch is in controlling position for both up or down control. When the magnet is deenergized, as the car enters the leveling zone an as the car switch is thrown to neutral position, the arms 81, 84 fall by gravity in clockwise direction conmeeting the terminals LD to LD and positioning the roller for engagement by a floor cam 28, which cam is of less length than the cam 25, the latter being herein, substantially twice the length of the former.

Thus, the switch is mechanically operable by the car as the same approaches the landing and after closing of the switch 24, to alternately break and make the circuit through the pairs of contacts LU, LU, LD LD. The form of car switchpreferably used is shown in Figs. 8 and 9, and comprises a suitable casing having non-rotatably mounted therein a disc of insulating material upon which are mounted the metallic segments 29, LU, LI), LU, LD, 30, 31, 32 and 33. The elements 29 are connected together by a suitable conducting element, not shown in Figs. 8 and 9, but indicated in Fig. 1, and the elements 38 and 31, LU and 30, and, LD and 32 are similarly connected. Mounted rotatably on a shaft 91 rotatable in the casing is an insulating element 92 to which is attached theordinary car switch contact members or brushes 93, 94, and the leveling contact carrying members or brushes 95, 96. The brushes 93, 94. each have mounted thereon two contacts slidable in suitable holders and adapted to be pressed toward the metallic elements of the member 90 by suitable springs. The brushes are respectively numbered 97, 98, 99 and 100, and are adapted to engage the metallic plates in a manner more fully herein after described. The holders 95, 96 each respectively carry two brushes 101 and 1%, 103 and 104, and these brushes are adapted for engagement with their stationary contact. plates only when the car switch is in neutral position, as shown in Fig. 8, in which position the brushes 101, 102 are respectively in engagement with metallic elements LU and LU and the brushes 103, 104 are respeetively in engagement with the metallic contacts LD and LD".

whenever leveler control cuts in and vice versa, making it impossible to operate both controls simultaneously and thus obtaining.

:mtomatic leveling control after the car switch is moved to neutral position, as hereinatter more fully explained. The various positions of the car switch are shown in the diagram.

Circuits.

The following circuits are provided: Main line circuits for either low or high speed up and down car switch operation; control, circuit for car switch low or high s eed in up and down direction; main line circuits for leveling in up and down direction; and cont rcl' circuits for leveling in up and 'down directions.

The system includes 'a main motor circuitcontroller of the general type having electric magnet reversingswitches, an accelerating magnet A operating in a well known manner to cutout the resistance forhigh speed, S indicating the shunt field windings for the motor, the usualor standard type of electro mechanical brake indicated by the magnet'B, and therefore a detailed description of these parts is not made herein, and likewise their operation is well known.

'The main line circuits for either low or followsi A e Starting at the plus side of the main lead to 12 through up switch 11, interpole windhi h eed u "car-switch o eration' are as D Sp 'ji ing 10"to contact 4,:md from contact 4 through the two following paths: Motr-" arma'ture2 to terminal- 7, switch 6 to terminal 8, also through switch 3, motor-armature 1 to 8, and from terminal 8 through starting resistance 23, switch 20, terminal 22, terminal 15, switch 14, terminals 16, 19, to negative main lead.

The main line circuit for either low or high speed down car switch operation is as follows: 7

Starting at the main line plus lead number 12 to 21,switch 20, starting resistance 23 to 8,

and from 8 through two paths, one through motor-armature 1, through switch 3 to 4,

and also from 8 through 6, 7, motor-armature winding 2 to 4, thence through interpolc winding to switch 11, 13, 18, switch 17, to 19, to negative main lead.

The control circuit for low speed car Switch up direction beginning at 40 on the negative lead, connects through 41 with magnet 42, magnet- 43, the two magnet-s being in series, from magnet 43 through the door switches D to one terminal of coil 27, of the leveling switch 26, the opposite terminal of this coil being connected with the car switch plates: 29, thence for low speed through car switch movable contact to 30 and up magnets 44, 45 to 12, thence to posi-.

tive main lead. For high speed up direction the circuit is the same to 29 of the car switch, thence to 31 through magnet 46 to 12, and positive side of main line. A control circuit for car switch low speed down direction starts at 40 and is similar to the other circuits to terminal 29 of the car switch, thence through car switch to 32 to down magnets 47, 48, to 12 and positive side of; main line. The control .circuit for high speed down is the same as the above to terminal 29 of the main switch, thence through 31, 46, to 12 and positive side of main line. The main line circuit for leveling in u direction is as follows: 7 r.

Starting at the plus side of the main line to 12 acro's'sll, interpolefwinding :10, terminal 4, armature 2, terminal 7, starting resistance 9, to 5, through switch 3.to armature 1, to 8, starting'resistance 23, switch 20, terminals 22, 15, switch 14,16, 19, to negative main line lead. The main line circuit for leveling in down direction starting at the plus side tol2, to 21, switch 20, starting resistance 23, terminal 8, armature .1, switch 3, terminal '5, starting resistance 9 to 7. armature 2 to 4, ,interpole winding 10, through switch 11', 13,;18,.switch l7,' 19 to negative side/of main line.., i The control 'rcuit.for' .levelingin up. rection starting zit-40,41, terminal 43,'of, open circuit contacting switch 24 to' terminal. 42' ofthe. same switch, which'is closed when the car is in;the. leveling zone, to finger66 of fioorselectoljup side 51,.to terminals'LUfl LU. of leveling switch 26f't0 corresponding.

terminal of the car switch, across 195 to LU, thence to 30, magnets 44, 45, to 12 and plus side of the mainline. Levelingin.

down direction beginning at 40-the circuit is the same to finger 66, thence to the down side 52 of the floor selector to L1), LD of leveling switch 26, across switch-LD to corre sponding terminal, the car switch to 32, magnets 47, 48, to 12 and plusside of the. main line.

The operation is as follows:

In Figure 1 the elevator is shown at theill-5 ergized to clear the switch arm of the leveling switch from engaging the inclines of the floor cams, especially when run past a floor at high speed which might cause injury to the switch. As soon as the car switch is moved to neutral the switch arm of the leveling switch is released to engage the inclines of any floor cam in its path for automatic control of the motor to bring the car to a landing position.

As the car approaches the floor the cam 25 first engages and' closes the corresponding switch 24, thus closing the circuit throu h the floor selector F and if, for example, te car is traveling in a down direction and the corresponding fingers of the particular floor are on the down side or engaged with the down segments of the selector, the car will slowly move in down direction until the cam 28-engages the armature of the switch 26 and throws it to the left breaking the circuit through contacts LD, LD. When the switch is held in the lefthand position closing contacts LU, LU and the corresponding selector fingers for "that'particular floor are'on the up side of the segments the car will move in an up direction until the contact is broken between LU LU.

The automatic leveling of the car is accomplished after the manually operated car switch is brought to its neutral position within a leveling zone, that is ata point wherein the switch'arm 81 of the switch 26 can be controlled by the cam 28. As long as the car switch is set for either an up or down control the magnet 27 is energized closing the .contacts EU and LU, allowing the car to continue its travel from floor to floor without interruption. The coil of the m'agnet 27 being in circuit connection with the motor controlling circuits of the car switch, for either up or down travel, is ineffective for motor control, and functions merely under such condition to hold the arm 31 of the switch 26in. a position free fromv actuation by the cam 28. In such position it-closes'th'e contacts LU and LU, but no circuit is established as the circuit controlled by the switch 26 is broken in the car switch; the brushes and 96 are free from contact respectively with the LU and'LD until the car switch is set to neutral position.

When the car switch is set to neutral posi tion the magnet 27 is deenergized, and the circuit connection for leveling control is established in the car switch so that a motor control by the switch 26 becomes effective whenevereither of the contacts L 1 and LU or L1) and LD are closed through the control of the cam 28. In traveling in an up direction, the car switch is brought to a neutral position, within the leveling zone wherein it is possible for the cam 28 to control the switch 26, for closing the contacts LU and I. i to continue the up travel of the elevator until the cam 28 releases the arm 81 of the switch 26 to aposition wherein all contacts are broken, as shown in Fig. 1, bringing the car to a stop. Should the car move upwardly beyond a point where the cam 28 cannot hold the switch from closing the contacts LD and LD the motor controlling circuit will be completed for a down control, until cut out by the cam actuating the switch 26.

Should the operator in either up or down direction more the car switch to the neutral position prematurely beyond the control of the cam 28 the switch 26 would more to a position closing contacts LD and LD either above or below the cam 28, and if beyond the cam 25 the car unless again manually cont-rolled would come to .a stop as the partial circuit line controlled by the switch 24 would be open, or the car would descend to the next lower floor, should by chance one of the switches 24 stick in aclosed position when the contact finger in circuit connection is upon the contact plate 52 so as to complete the motor control cir cuit.

If there is over-travel of the car beyond the floor in either direction for any reason, the leveling device switch in conjunction with the floor selector will continue to adjust the car, although a number of oscillations may be necessary, and the car will be stopped accurately at the proper level.

It will be noted that when the car switch is in neutral position magnets 42, 43 are in operation and regardless of whether or not the doors and door switches are open or closed the leveling device will operate automatically, as long as the car switch is in neutral position and the car in the leveling zone. The circuit for closing magnets 43, 42 for high speed or ordinary operation between leveling zone is however controlled through the door switches and those magnets cannot be operated when the door switches are open.

The various positions of the car switch are shown in the diagram and when the switch handle is thrown to either side of the center or mutual position, to engagement with the plates 29, the motor armature's are put in parallel relation and the car will operate similarly to the ordinary elevator, using the inter-pole shunt motor with three to one control. Whenever the car switch is brought to a neutral position the contacts LU, LU", and LD, LD are connected together, and if the car is in the leveling zone the same will move at a very slow speed owing to the fact that the armature windings l and 2 are then in scrics. and the starting resistances 9 and 23 are pern'iancntly in series therewith, reducing the current, for example, to 50 ampercs and corrcspour'liugly reducing the speed below 150 R. P. M. while fill.

' control" system, saidswitch bein at the same time maintaining the original torque. 4

This device is applicable to all classes of elevators, but its most important application is for freight elevators. The leveling device will operate automatically within the leveling zone whenever the car switch is moved to neutral position, the leveling operation taking place regardless of -whether the door or gates are open or closed.

If the car should over-run in either direction, for instance in an up direction, the leveling device will operate to reverse its direction and will continue to make such adjustments as are necessary until the car is properly and; accurately brought to a level with the desired floor.

-Having described my invention, What I claim is: v

1. In anelectric elevator, the combina tion with-a car,':an: electric, hoisting motor. therefor, said motorhaving "a double wound armature and commutator for said armature winding, electro-magnetically operated switch deviceslfor alternately connecting the windingseriesor parallel to obtain a variation in motor speed, a manually operable car, switch for-v normal elevator hoisting motor; control controlling -the electric circuit etically operated switch device, and: rendering the same'fiectivein'the active controlling-positionsof said ca'r switch for obtaining a'znormal' running-speed of the motor and alternately-forobtaining an auxiliary running speed ofi-ther motor, andswitchdev'ice's-operable by the elevator car for controlling the motor with the elevator car.in'landing'zone for bringing=the car to a'1evel with the' landing;

s2 'In an :elevator 'system' 'in combination with a car,=- an elevator :"hoistingmpparatus therefor including a :motor havin two a'rmature windings,- switches for obtaining series or parallel-relation of said: windings respec-j tively to' give slow*and"-fast inotor speeds,

an electro-me'chanical leveling :apparatus' and electric leveling. control system therefor for obtaining car leveling movements in reverse directions and for stopping the car at the floor, and a car switch electrically connected with said motor and leveling control system ='operable one position only for simultaneously bringing said motor windings in-seriesrelat-ion, and energizing the leveling further adapted in other positions for ordinary elevatorcontrol f -3. In an 'elevator system in combination with a car, an elevator hoisting apparatus therefor including a motor having two identical armature windings and commutators, switches for obtaining series or parallel relation of said windings respectively to give slow and fast motor speeds, an electro-me- 'cha'nica-l system for obtaining-car leveling movements in reverse directions and for stopping the car at. the floor, and a car switch operable in one position for simultaneously bringing said motor windin s in series rela tion and energizin the leve ing control sys-' tem and further a apted-when in any other position forobtaining parallel relation of the motor windings and ordinary motor control.

4. In an elevator system in combination with a car, motor hoisting apparatus including two identical motor windings, switches for alternately obtaining series and parallel connection of said windings respectively for slow and high speed motor operation, an electromechanical leveling system. for stopping the car at the floor, a car switch for control ing saidwinding switches,'motor, and electro-mechanical leveling system and operable in a single positiononly for automatically, electrically; energizing. the leveling system and operating the same simultaneously with the actuation of the winding controlling switches to obtain. series connections, and operable in every otherposition for ordinary elevator control simultaneously with the actuation of the winding switches to obtain parallel connection; I

5.. In an elevator-system in. combination with a car, anelectrichoistingmotor having two identicalfarmaturei windings, switches for obtaining alternate series or parallel connection of the windings respectively for low and high speed-motor operation, a car switch for control of the motor for ordi nary elevator operation simultaneous with winding switch-actuation for parallel connection, and for independent winding switch actuationiorseries connection, anelectro mechanical leveling system: for. stopping .the car at the landingincludinga switch on-the car and. cams on the hatchway for I controllingthe switch, said-'leveler system automatically,electrically. energized by the car switch simultaneouslywiththe actuation of the "winding switches to obtain. series connectionand non-operable therebywhen in other-control positions .to-obtain ordinary car' movements, and. winding switch actuation for parallel winding connection.

6. In an elevator system incombination with a car, an elevator hoisting apparatus therefor including a motor having two identical armature windingsand 'commutators, switches for obtaining series or parallel relation of said windings respectively to give slow and fast motor speeds, an electro-inechauical floor leveling apparatus and anelectrical control system therefor, for obtaining car leveling movements in reverse dire-1'- tions and for stopping the car at the floor, and a switch upon the car adapted to electrically control said leveling apparatus for obtaining leveling movements of the car, cams at each floor for mechanically actuating said switch, and a car switch electrically llll connected with said motor winding switches and leveling apparatus operable in one position only for simultaneously bringing said motor winding in series relation and activating the leveler control system, and operable in all other positions for obtaining ordinary motor control and simultaneous winding switch actuation for parallel connection.

7. In an elevator system-in combination with a car, an elevator hoisting apparatus therefor, including a hoisting motor having two identical armature -windings and switches for obtaining series or parallel relation' of the windings respectively to o!)- tain ordinary speeds and a sub-slow speed, a

leveling switch on the car in circuit connection with the motor for obtaining reverse motor movements, said switch mechanically operated by a cam at each floor, switches for closin the control circuit to the switch adjacent t e floor, a car switch in circuit connection with the motor through the leveling switch and with the winding switches adapted in neutralposition for operating the winding switches simultaneously to bring the motor windings in series relation, and energizing the leveling switch to-obtain subslow motor speeds'for' motor leveling movements, said switch further adapted in any other position for ordinary elevator control, simultaneous operation of the winding switches to obtain-paralleled relation of the windings and causing the leveling switch to be inactive.

8. In an elevator system in combination with a car, an elevator hoisting apparatus therefor, including a hoistin' motor having two identical armature win ings, winding switches for alternately obtaining series or parallel relation of the windings respectively to give slow and ordinary motor speeds, a. leveling switch upon the car in circuit connection with the motor for controlling the same for reverse leveling movements and for stopping the car at-the-floor,.cams at each floor for actuating the-switch, and near switch 1n circuit connection with the motor and the winding switches for independently putting the latter in series relation and for closing the circuit through the leveling switch when in neutral position and for independently operating the win ing switches to obtain parallel winding relation, breaking the circnit through the leveling switch when in other than neutral position and obtaining ordinary elevator control in non-neutral positions.

9. In an elevator system in combination with a car. an elevator hoisting apparatus therefor, including a hoisting motor having two identical armature windings and commutators, winding switches for obtaining series or parallel relation of the windings respectively to give sub-slow and ordinary motor speeds, a leveling switch on the car in circuit connection with the motor control de vices operable by a cam at each floor for obtaining motor leveling movements and f r automatically stopping the car at the fiooxg and a car switch in circuit connection with the winding switches and leveling switch operable in one position for simultaneously operating the winding switches to give a series relation of the windings, andclosing the circuitto the leveling switch to give an auto matic leveling operation, and in all other positions for obtaining ordinary motor control and actuating the winding switches to give a parallel relation of the winding.

10. In an elevator system in combination with a car, an elevator hoisting apparatus therefor, including a hoisting motor having identical armature windings-and commutator, winding switches for obtaining or parallel relation of the windings respectively to give sub-slow, and ordinary motor speeds, a leveling switch on the carin circuit con-' nection with the motor control devices operable by cams at each floor for automatic leveling control and for stopping the car at the floors, switches for closing-the control ircuits of the leveling switch when the car is adjacent the floor, a can switch adapted in neutral position to simultaneously close the circuit of the leveling switch to'the motor and operatefthe winding switches forobtain ing series relation to the windings, said ca-r switch adapted in all other positions for obtaining ordinary motor control, simultaneous windi switch actuation inp'arallel con nection, ah breaking the circuit through the leveling switch.

11. In an elevator system in combination with a car, an elevatorhoisting apparatus therefor, including a hoisting motorhaving two identical armature windings, and switches for obtaining series or parallel re lation of the windings respectively to obtain ordinary speeds and a snblow speed, a leveling switch on the .car in circuit conhection with the motor for obtaining motor levcling movements, a cam at-each floor for actuating the switch, aswitch at each 1001 for closing the control circuit to the leveling switch, a car switch in circuit connect-ion with the motor through the levelingswitch, and with the winding switches, adapted. in one position for simultaneously operating the winding switches to. bring. the motor windings in series relation, and to-energize the leveling switch circuit, said-car switchfurther adapted in other positions to obtain ordinary elevator control, operation of the winding switches to obtain parallel relation of the armature windings, and t0 makev the leveling switch inactive.

12. In an elevator system in combinationwith a car, an elevator hoisting apparatus therefor, including a hoisting motor having a double armature winding, winding switches for alternately obtaining series or parallel the leveling switch to the motor and start the relation of the windings respectively to give leveling operation, and in other positions for slow and ordinary motor speeds, an electrocontrolling the winding switches to obtain mechanical leveling switch on the car for parallel winding relation, to break the circuit controlling leveling movements of the motor, through the leveling switch to the motor and 15 a cam at each floor for operating the leveling obtain ordinary elevator control.

switch and a car switch operable only when In witness whereof, I hereunto subscribe in a single position for controlling the windmy name.

ing switches to obtain series relation of the motor windings to close the circuit through ARTHUR J. LIEBENBERG. 

